Machines incorporating intermeshing rotors have been described. See Chomyszak U.S. Pat. No. 5,233,954, issued Aug. 10, 1993 and Tomcyzk, U.S. Patent Application Publication 2003/0111040, published Jun. 19, 2003. The contents of the patent and publication are incorporated herein by reference in their entirety. However, improved efficiencies in these machines are desired.